Valve structure and fire protection sprinkler system including same



Nov. 28, 1967 3,355,728

J. B SMITH VALVE STRUCTURE AND FIRE PROTECTION SPRINKLER SYSTEM INCLUDING SAME INVENTOR James 5.527261% W 0'6 06 A ORNEYS Nov. 28, 1967 3,355,728

J. B. SMITH VALVE STRUCTURE AND FIRE PROTECTION SPRINKLER SYSTEM Filed June 2'6, 1964 INCLUDING SAME 5 Sheets-Sheet 2 (W '3. James 5. Sim/5h A ORNEYS J. B. SMITH VALVE STRUCTURE AND FIRE PROTECTION Nov. 28, 1967 SPRINKLER SYSTEM INCLUDING SAME Filed June 23, 1964 3 Sheets-Sheet 5 I Y B 6- 0568566 OPE/V E w m M% Wm W m s 0 W 6 J 0 5 5 aw w w 009 a United States Patent VALVE STRUCTURE AND FIRE PROTECTION SPRINKLER SYSTEM INCLUDING SAME James B. Smith, Wellesley Farms, Mass, assignor to Factory Mutual Research Corporation, Norwood, Mass,

a corporation of Massachusetts Filed June 23, 1964, Ser. No. 377,252 17 Claims. (Cl. 340-196) ABSTRACT OF THE DISCLOSURE The present disclosure includes drawings and a specification directed to a valve position indicator and a fire protection sprinkler system. The valve position indicator generally includes a coil-containing valve member mounted for movement within a coil containing valve seat. When either of the coils is energized by a voltage source, a current is induced in the other coil, the magnitude of the induced current as read on an indicator device being indicative of the relation of the movable valve member to the Valve seat. The valve indicator of the present invention has the advantage of providing a check on the operativeness of the indicator, since even when the valve is in a fully open position, whereby the induced current is at a minimum, the presence of the minimum current serves to indicate that the valve indicator is functioning properly. The fire protection sprinkler system generally comprises buried waterfeed mains which are adapted to feed water to any number of buildings to be protected. The buried mains are provided with valves each of which is equipped with a valve indicator as previously described. By virtue of the reliability of the valve indicator of the present invention, it is always possible to determine whether the valves are opened or closed.

This invention relates to valve position indicators and, more specifically, to dual electric coil valve position indicators.

Valves which contain mechanisms to indicate the position of the valve actuator in relation to the valve seat are well known and take a great variety of different forms. One of the most common for-ms of such mechanisms providing an indication of the valve position includes a mechanical connection from the valve actuator to the outside of the valve body to a pointer, flag, target, or some other form of indicator. Also, various forms of electrical valve position indicators are in use. Generally, this latter type of indicator contains added stru ture between the valve actuator and the valve seat which is connected to appropriate electrical circuitry to provide the necessary indication. Usually, the added structure takes the form of a pair of switch contacts, a movable arm on a potentiometer, or the like.

Such prior art devices, however, whether mechanical or electrical, are not completely fault-free. For instance, any failure in the connection between the valve actuator and the indicator portion of the device would result in inaccurate indications. In other words, the valve may be functioning improperly and the information of such improper operation may not be indicated due to the breakdown between the valve operating portion and the indicating portion.

In certain areas it is important to have dependable intelligence as to the position of a valve. Further, the

means to provide this intelligence should also be capable of being checked so that there is the maximum degree of assurance that the intelligence is accurate. One area where such extreme accuracy is necessary is that involving automatic sprinkler systems which are employed in the fire protection field. [Note: For purposes of identification now, and throughout the remainder of the application, the following definitions will be used. Risers are the vertical pipes connected to the underground piping. The horizontal pipes supplying the risers are called feed means, while the pipes directly supplying the lines in which the sprinklers are placed are referred to as the cross mains. Finally, the lines of pipe in which the sprinklers are directly laced are designated as branch lines] In the conventional water sprinkler systems an independent water distribution network is provided. Feed mains which supply the water to the building protectedare buried below the frost level of the ground. They are connected between risers which supply cross mains in the building, and a main supply of Water. Needless to say, it is imperative to know at all times that water is available at the branch lines, which are connected to the cross mains and contain the sprinkler heads, when the demand arises. Also, after a fire is brought under control it is necessary to turn off the water to the risers to prevent excessive water damage to the building and its contents.

To accomplish the desired fire protection results, a control valve is normally buried along with the feed main at a safe distance from the building. The control valve is likewise buried below the frost level and, as can be appreciated, means which are both accurate and dependable are required to show the position of this valve at all times. Indicator posts, which are controls extending above ground, can be provided to operate such underground control valves and provide an indication of the valve position. An important feature of such indicator posts is the inclusion of a target or indicator that is visible through an opening in the posts which shows whether the control valve is open or shut. Generally, such indicator posts, which are commonly used with gate valves, contain stems that operate the underground control valve and simultaneously move the target to provide the necessary indication.

Where one building is being protected such indicator posts create no problems of supervision and checking. However, such a single unit is still susceptible to tampering and can be closed by unauthorized persons either before or during a fire. Further, the unit suffers from an inability to provide fault-free indications of the position of the control gate valve in that the mechanical connection between the valve actuator and indicator portion of the posts can rust, bind, or break olf. In other words, there is no complete assurance that when the valve stem is turned above ground, the actual valve actuator and seat cooperate to either open or shut as directed.

With such post indicators a supervision problem arises when an industrial plant comprising a plurality of buildings is protected. In such a complex, many indicator posts are required and they are usually spread out throughout the entire plant area. To assure safe protection for the buildings the control valves must be checked frequently. Very often, weekly checks of each control valve are required to meet standard safety requirements. Necessarily, a long tour of the plant area results which takes up much time, not only to complete the tour, but also to physically check the valve actuator to make sure that it is at its limit of travel and actually fully opened. Since, as mentioned above, such supervision is done weekly, the expense and the time required to make this tour fifty-two times a year becomes significant.

With this type of a checking system, there is also a possibility that one or more of the control valves might be shut between the weekly tours. Were a fire to occur after such shutting, severe damage and possibly a total loss of the building could result. Further, because of the access to the control valve by individuals, it is possible that someone, even with good intentions, could shut oil": the Water and allow the fire to proceed out of control and spread further.

In order to decrease the time required to check each control valve of a widespread fire protection sprinkler system, it has been suggested that butterfly valves be used to control water flow into a building. Such butterfly valves can also contain indicating means extending upwards from the buried valve to provide a visual indication of the position of the disk with regard to the valve seat. A post indicator valve assembly of this type, however, although reducing the time necessary to complete a tour of the system, still suffers from the disadvantages of possible tampering between inspections and careless operation during a fire. In addition, such valves suffer the deficiencies of similarly constructed post indicator mechanisms in the unreliability of the mechanical connection between the valve and indicator portion of the posts.

As a result of the inadequacies of the present sprinkler valve control and indicating mechanisms, a need has arisen to provide up-to-date means for fire protection in both single buildings and larger plant complexes. In this latter area, closer and more accurate supervision of each and every control valve is necessary. As far as possible, the human element should be removed and the sprinkler feed system made fully automatic. For instance, if the valve position indication and control over each valve could be concentrated at a single station, most of the problems would be overcome. In such a system a responsible person would have control over each of the control valves and also have dependable intelligence available as to the position of each valve. In this manner control could be maintained over the water supply to the various buildings and losses both from fire and water would be kept to a minimum. Emergency decisions by people not knowing the overall problems would be avoided and costly mistakes reduced. Finally, if the control valve could be buried completely Without any extensions above the ground which might be tampered with or otherwise cause the valve itself to become inoperative or the indication false, the reliability and dependability of the fire protection system would indeed be great.

In accordance with the present invention, novel means have been provided to permit a remote indication of the position of a valve with a higher degree of dependability than heretofore has been possible. By virtue of the present invention, the necessity of actually checking the valve at its site is eliminated and the possibility of erroneous indications of the valve position substantially decreased. Finally, remote indication of the position of each of a plurality of valves is made feasible, thereby allowing easy and effective supervision and control over each or all the valves.

It is accordingly a primary object of the present invention to provide novel valve position indicating means.

It is still another important object of the present invention to provide a novel electrical valve position indicator which is simple yet extremely accurate.

It is a further object of the present invention to provide a novel valve position indicator that provides dependable intelligence of the position of the valve while utilizing few components. g

It is still another important object of the present invention to provide novel dual electric coil valve position indicators for sprinkler control valves which permit the valves to be buried without any above-ground indicator post extensions and yet allow accurate indications of the position of the valve at a remote point.

It is a further important object of the present invention to provide novel valve position indicators for buried control valves which make possible quick and accurate supervision of a plurality of such valves throughout an entire feed main system and which reduce the possibility of tampering or improper operation of such valves.

It is still another object of the present invention to provide means for achieving an accurate indication of the position of one member of a valve with regard to the other.

It is a further object of the present invention to provide an electrical indication of the position of the disk with regard to the seat of a butterfly valve, as well as to provide an indication that the electrical portion of such an indicator is operative.

It is still another object of the present invention to provide a remote indication of the position of a plurality of control valves at a single location and thereby dispense with the necessity of checking each valve at its site.

These and other important objects and advantages of the present invention will become more apparent in connection with the ensuing description and appended claims, as well as the attached drawings wherein:

FIG. 1 is a partial vertical sectional view of a butterfly valve embodying the principles of the present invention;

FIG. 2 is a section-a1 view of the valve taken along the lines 2-2 of FIG. 1;

FIG. 3 is a schematic representation of a plurality of the valves of the present invention utilized in a sprinkler system for a plant complex;

FIG. 4 shows the valve and indicator of the present invention buried in the ground adjacent to a building being protected; and

FIGS. 5 and 6 are graphs showing the output voltage of the device for various positions of the disk with respect to the valve seat.

As previously indicated, the present invention involves novel valve position indicator means, and in particular a valve position indicator for sprinkler control valves. In its broadest aspects, such novel indicator means involves operation based on a transformer principle between a pair of adjacent windings or coils. Preferably, one winding is placed on a movable member of the valve, while the second winding is placed adjacent to the first Winding on a stationary member of the valve. Upon energization of the first winding, which can be considered the primary of the transformer, a voltage will appear on the second Winding, which can be considered the secondary of the transformer. Among other conditions, the magnitude of the voltage is dependent upon the position of the primary winding with regard to the secondary winding and upon the frequency of the energizing voltage. Thus, there is provided simple means for indicating the relative position between movable and stationary members of a valve. In addition to this broad concept, the present invention contemplates more specific inventive concepts including the pro-vision of particular structural elements which are peculiarly Well adapted to effect the broad objects of the present invention, as will be more particularly described hereinafter.

While the broad inventive concepts of the present invention are not restricted to particular types of valves, the invention to which this application is directed can be best described in terms of specific sprinkler control valves which can be utilized in fire protection systems. For purposes of clearly describing the inventive concepts herein involved, a butterfly valve is illustrated.

The basic butterfly type valve in which the electrical indicating means within the contemplation of the present invention is incorporated is best illustrated in FIGS. 1 and 2. As shown therein, this valve, indicated generally by reference numeral 8, comprises a stem or shaft having a passageway 11 and to which is fixed a movable valve member in the form of a disk 12. The disk 12 cooperates with a valve seat 14 of a valve body 16. In normal operation, the valve 8 is placed between a pair of adjoining pipe sections 18 and 20 having flange portions 22 and 24, respectively. The assembly is fastened together by a plurality of machine bolts 26 extending between the flange portions 22 and 24 and is held together by a plurality of nuts 28.

In FIG. 1, the bottom of the shaft 10 is shown as being mounted on a bearing cap 32 which is held in place by a plurality of screws 34 extending into the valve body 16. A sealing ring or washer 36 is placed between the bearing cap 32 and the valve body 16 to provide a watertight fitting for this portion of the valve, yet allow for ease of construction and maintenance, if such is ever necessary.

At the upper portion of the shaft 10 there isincluded a pair of O-rings 38 and 40 in chambers 42 and 44, respectively, formed in the valve body 16. The purpose of the O-rings is to provide the necessary watertight protection for the valve assembly while allowing rotation of the valve shaft 10 with respect to the valve body 16. An opening 46 is formed in at least one-quarter of the circumference of the valve shaft 10, the purpose of which will be more clearly described below. The shaft 10 can be extended to either a manual control, such as a hand crank or hand screw, or preferably to a power control, which can be electrical, hydraulic, or a combination of both, which control provides the necessary rotational force to the shaft. The preferable power control is normally located in close relation to the valve operating members and can even be included in a portion of the valve body itself, thereby forming a single compact unit.

The disk 12 is most clearly shown in FIG. 2, where it can be noted that it is thickest at its center and thins down toward its periphery. When turned in the direction of pipe flow, which is its fully opened position, this streamlining effect of the disk 12 provides less flow resistance and creates less turbulence in the fluid flow. The disk 12 can be constructed of two metal halves fused or otherwise joined together, or it may be made as a single metal piece as shown in FIG. 2. Also, the disk 12 can consist of a molded plastic material, if desired. The diameter of the disk 12 is preferably slightly larger than the inner diameter of the valve seat 14 in order to provide a more positive connection between both elements when the valve is in its fully shut position. The disk 12 and its shaft 10 are adapted to rotate 90, with the angle of rotation of the disk from its fully closed position to an intermediate position being designated by the angle 9.

The valve seat 14 is preferably constructed of a rubber material, as depicted in FIG. 2, or can be metal as well. When the valve seat 14 is made of rubber, its outer ends 48 and 50 are carried around an inner circumferential portion 52 of the valve body 16 to form an outer gasket.

when the valve is placed between the flange portions 22 and 24. Of course, the end portions 48 and 50 of the valve seat 14 are compressed to form a tight fit between the valve body 16 and the flange portions 22 and 24 to thereby prevent any leakage of the fluid passing through pipe sections 18 and 20 and the valve 8.

Embedded in the disc 12 is a coil, indicated by reference character 54, comprising a plurality of turns of wire. The wire is of the insulated type and the plurality of turns form a winding which carries current near the outer periphery of the disk 12. The coil is preferably enclosed completely in the disk 12 in a passage or chamber 56 formed therein. The chamber 56 has openings leading into the passageway 11, and in this manner the wires of the coils 54 can be connected to an external cable. More specifically, a pair of lead wires 58 and 60 are connected between the coil 54 and a cable 62 extending from the 6 valve body 16. The wires 58 and 60 pass up through the passageway 11, through the opening 46 in the shaft 10, and through a cavity 64 formed into the valve body 16 to the external conductor or cable 62.

A second coil, designated by reference numeral 66, lies between the valve seat 14 and the valve body 16. This coil is also comprised of a plurality of turns of an insulated wire and is onnected through a pair of leads 68 and 70 to the cable 62. The cable 62, in this instance, can be of the four conductor armor-shielded type. The leads 68 and 70 extend from the cable 62 through the cavity 64, down through a passageway 72, formed in the valve body 16, to the coil 66. The position of the coil 66 between the valve seat 14 and the valve body 16 provides a winding with both electrical insulation from the coil 54 in the disk 12 and watertight protection from the fluid flowing through the butterfly valve 8. In actual practice the rubber valve seat 14 can be vulcanized around the projection 52 of the valve body 16 with the coil 66 having already been placed thereon. In this manner, a thoroughly insulated winding is provided.

To provide the watertight protection necessary for the electrical connections of the valve position indicator, cable 62 is placed into the cavity 64 and is held in a threaded hollow extension 74 of the valve body 16 by means of a threaded bushing 76. The bushing 76 contains a watertight seal 78 encircling the cable 62 which seal is pressed between the interior portion of the bushing 76 and the exterior portion of the threaded extension 74.

The position indication of the present invention is based on a transformer principle, as mentioned above. A transformer generally consists of two coils electrically insulated from each other and positioned in adjacent relationship, though the two coils could be connected electrically in series for operation as an autotrans-former; the general principle, however, remains the same for both arrangements. An alternating current in one winding sets up an alternating magnetic flux around this winding. Most of this flux links with the other winding and induces in it an alternating electromotive force. Power is thus transferred from one winding to the other via the flux induced by the first winding. Normally, the winding to which the voltage is supplied is called the primary and that from which the voltage is delivered is called the secondary. Either winding may be used as the primary as desired. The voltage appearing in the secondary winding is dependent upon the amount of flux lines which cut the coils of the secondary winding, as well as the number of turns in each of the windings. The more magneti flux lines cutting the secondary winding, the larger the output.

The operation of the subject invention will now be described through reference to FIGS. 1 and 2 of the drawings and the graphs of FIGS. 5 and 6. For purposes of illustration, the coil 54 in the disk 12 will be considered as the primary while the coil 66 in the valve seat 14 will be considered as the secondary. It should be pointed out, however, that the device will operate as well with the coil 66 acting as the primary and the coil 54 acting as the secondary. 1 I

With the disk 12 in its fully closed position, as shown by the full lines of FIG. 2, an alternating current voltage impressed across leads 58 and 60 will create an alternating magnetic field in the area adjacent to the coil 54. Since the coils 54 and 66 are in their closest relationship, the magnetic flux lines will induce a voltage into the coil 66 that will be at its maximum value. As the valve shaft 10 is rotated in a counterclockwise direction looking at FIG. 2, the distance between coils 54 and 66 becomes larger as angle 6 increases. The number of flux lines cutting through coil 68 accordingly decreases, and the voltage output appearing across leads 68 and 70 also decreases. When the disk 12 assumes a position parallel to the flow of the fluid through the valve 8, 0 is and the amount of flux lines cutting through the turns of coil 66 are at a minimum, causing the output voltage to de- 5 crease to almost zero. Thus, the magnitude of the voltage induced in the secondary circuit provides a direct measure of the condition of the valve, be it fully open, fully closed, or at some intermediate position between these extremes.

FIGS. 5 and 6 are curves showing the voltage output of the secondary coil 66 at various values of the angle 0. The curves were plotted from data taken during the tests of the dual coil electrical indicator wherein a 60 cycles per second alternating current of 11.8 amps was passed through the primary coil 54. The primary coil 54 consisted of five turns of number 18 wire, while the secondary coil 66 consisted of fifty turns of number 28 wire. The abscissas of the graphs contain values of the angle 0, while the ordinates contain the secondary voltage output and the value of cos 0.

The curve designated as B in FIG. 5 shows the actual value of the secondary voltage output and was plotted from values taken when the disk 12 was at the 0, 16, 33, 49, 65, 82 and 90 degree values of angle 0. The dash curve designated as A shows a theoretical curve of cos plotted from the same values of 0. It is interesting to note that curve B follows quite closely the value of cos 0 depicted by curve A. This is significant in that the rate of change of voltage, i.e., the slope of the curve B, is greater at a point when the disk 12 first changes from its fully open position than when the disk approaches its fully closed position. A larger rate of change of voltage takes place at the former time, which change can be utilized to operate an alarm or similar device to apprise an operator of this deviation from the open valve condition.

In normal operation the valve 8 is at its fully open position, which allows water to pass from the feed mains to the risers in the structures being protected. As can be seen from the curve B of FIG. 5, a small voltage output appears across the lead lines 68 and 70 with the valve in this fully open position, which voltage signifies that the electrical portion of the indicator is operative and that the valve is in its fully open position.

If for some reason the disk 12 is caused to rotate toward its closed position, a sudden change in voltage takes place in the secondary coil 66. By the use of appropriate sensors, an alarm or other Warning can be actuated to indicate this change of position. Necessary steps can be taken to correct any problems that may have developed at this time.

As may be seen in FIG. 5, the maximum voltage output of the secondary winding 66 occurs when the valve 8 is in its closed position. Thus, by the use of indicators which operate on a voltage magnitude basis, the position of the valve 8 is known at all times.

The curve depicted by FIG. 6 shows a second test taken of a valve with the angle 0 being at 0, 15, 30, 45, 60, 75 and 90 degrees, respectively. Curve B again shows the actual value of the output voltage, while curve A was plotted from the values of cos 0 at the same angular values. The X-axis and Y-axis labeling are the same as in FIG. 5, and the current and number of turns of wire of both coils are the same as the data previously used. It is interesting to note that curve B again approximates the cosine 0 curve A.

Thus, with the device of the subject invention there is always provided direct intelligence of a valve position. It is inconceivable that the valve may be closed without moving the disk relative to the seat and, therefore, whenever the disk moves in relation to this seat, an indication of this fact will be transmitted through the output winding. Further, a supervisory current is always provided through the primary coil and if there were any break in either the primary or secondary circuits an indication would be presented in the form of a no-voltage reading across the secondary in the fully open valve position, indicating the non-operativeness of the circuit. This low cost safety feature is made possible by the present invention since, as shown in FIGS. and 6, in the fully open valve position the supervisory current causes a very small voltage in the secondary.

Up to this point the discussion has been mainly concerned with a single butterfly valve embodying the concept of the present invention. The use of the dual coil valve position indicator in an overall fire protection sys tem will now be described.

FIG. 3 illustrates a schematic plan of an industrial plant which contains a sprinkler fire protection system. The industrial plant depicted consists of a plurality of buildings, some of which are identified by reference numerals 80, 32, 84 and 36. The building is shown as being larger than the remaining buildings. Water is supplied to the buildings by means of a buried feed main 88 which is connected to a gravity feed water tank 90.

Because of its larger size, building 80 contains a pair of risers 92 and 94 which allow independent operation of two separate sprinkler sections, either on a vast single floor or on each of two floors. Connected between the riser 92 and the feed main 815 is a butterfly control valve 96, similar in all respects to valve 8 illustrated in FIGS. 1 and 2. A second identical butterfly control valve 98 is provided to control the flow of water to the riser 94 and the remaining sprinklers controlled thereby. In this manner water can be shut off from the whole building by turning valve 96 to its closed position, or only a portion of the building by controlling valve 98. If desired, another control valve can be included to operate with riser 92 without affecting the operation in riser 94.

As shown in FIG. 3, the buildings 82, 84 and 86 have their respective risers 1110, 162 and 104, as Well as their respective butterfly control valves 1%, 108 and 110, which are identical to the valve 96. Further, a valve may be used to control various sections of the plant complex. For instance, a butterfly control valve 112 is utilized to control the water flow to buildings 84 and 36 without affecting flow to buildings 80 and 82.

In FIG. 4 there is shown the actual physical relationship of a valve used in accordance with the present invention in a fire control sprinkler system and in its surroundings. A butterfly control valve 131 is buried in the ground 132 outside the foundation 134 of a building to be protected. The valve 130 is connected in the feed main between pipe sections 136 and 138. The water, therefore, passes through the pipe section 136, the valve 131 the pipe section 138, a ninety degree L 140, a riser 142, to the remainder of the system.

Extending from a junction box 144 mounted on the valve 130 is a cable 146 containing the necessary conductors for carrying the electrical signals designating the position of the valve, as well as any control signals, to a valve actuator control assembly mounted in junction box 144. Such controls are well known and form no part of the present invention.

To provide the necessary indication of the position of each valve at a central point, an electrical cable 114 is buried alongside the feed main 88 when the sprinkler system is installed. Connector cables 116, 118, 120, 122, 124 and 126 are connected between the cable 114 and each of the control valves 96, 98, 106, 108, and 112, respectively. The cable 114 is then connected to a main control point or control house 128, where all the information pertaining to the position of each valve is readily displayed. In this manner the information pertaining to the position of each valve is located at a single point rather than throughout the plant complex.

With the valve position indicators of the present invention, efiective supervision of the valves before a possible fire, and effective control of the valves during a fire, are obtained. Authorized persons in the control house have very reliable and dependable indications of the position of each valve and can take proper action as the occasion demands. In such a system, it is not necessary to get the indication of the position of a valve at each location,

.9 I but merely to get such indications at one central location. Much time is thus saved and better supervision results.

Valve actuator controls which are electrically controlled can be buried along with each valve to control the position of the valve. Such controls would enable the valve to be moved from its open to its shut position as desired. The transmission of the control signals to each valve can be accomplished by the use of wires added to cable 114. With this added step of control, each valve can be opened or shut from the control house 128 both for testing purposes and actual fire fighting. With such remote control, a valve may be buried completely without any means at the location of the valve to control its opening and closing. It can be seen that such a system would be essentially foolproof.

As will be understood, the novel valve position indicator of the present invention makes feasible a truly faultfree sprinkler control valve construction. The broad inventive concept is not, of course, limited to the butterfly valve of the present invention, the broad concept involved residing in the use of a pair of coils integrally mounted in a movable and fixed member of a valve to electrically indicate the position of one valve member relative to the other.

This invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restricted, the scope of the invention being indicated by the ap* pended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A valve structure comprising a hollow shaft, a disk mounted on said shaft, a first coil embedded in said disk, said coil having leads extending therefrom through said hollow shaft for connection to a source of alternating voltage, a valve body having a passageway formed therein, a valve seat mounted on said valve body, a second coil positioned between said valve seat and said valve body, said second coil having leads extending therefrom through said passageway for connection to an indicator device, wherein said disk is adapted to rotate in its radial plane to thereby vary its position with regard to said valve seat and change the magnitude of a voltage induced in said second coil by said first coil after said first coil is energized by the voltage source, said induced voltage magnitude being dependent upon the position of said disk and said valve seat.

2. A valve position indicator comprising a valve, control means for moving said valve into an open or shut position, first electrical means associated with said con trol means for producing lines of magnetic flux, stationary means cooperating with said control means for allowing or preventing fluid flow through said valve, second electrical means associated with said stationary means for intercepting said lines of flux, and circuit means responsive to the number of lines of flux intercepted for transmitting intelligence indicating such number of intercepted lines, wherein the number of lines of flux intercepted is indicative of the position of said movable control means with relation to said stationary means.

3. A valve position indicator as defined in claim 2 wherein said first electrical means includes a coil which produces a varying magnetic field upon energization by an alternating voltage, and said second electrical means includes a coil which produces an induced voltage in response to said varying magnetic field.

4. A valve position indicator as defined in claim 3 wherein said coil of said second electrical means produces no induced voltage when said first electrical means is inoperative.

5. An electrical valve position indicator comprising a valve, a disk rotatably mounted in said valve, a seat T parallel to the axis of said first coil, wherein the trans former coupling between said first and second coils is changed as the disk is rotated to thereby provide an indication of the position of said disk within said seat.

6. A valve position indicator comprising a movable valve member, a first coil arranged on said valve member, a valve seat, a second coil arranged on said valve seat adjacent to said movable valve member, one of said coils being connectable to a source of alternating voltage and the other of said coils being connectable to an indicator device, wherein said one coil induces a voltage in said other coil when energized by said voltage source, the magnitude of said voltage source being dependent on the position of said valve member and said valve seat.

7. A valve structure comprising a valve member, a first coil arranged on said valve member, a valve seat, asecond coil arranged on said valve seat adjacent to said valve member, said valve member being movable with respect to said valve seat so as to vary the extent of coupling therebetween, and means to vary the coupling between said coils by moving said valve member in relation to said valve seat.

8. In a valve position indicator, a valve disk, a valve seat, a pair of coils relatively movable with respect to one another so as to vary the extent of coupling therebetween, one of said coils being stationary and the other of said coils being movable, said movable coil being mounted on said valve disk for movement relative to the stationary coil and said stationary coil being mounted on said valve seat encircling said movable coil, and means to vary the coupling between said coils by moving said disk in relation to said valve seat.

9. A valve position indicator as defined in claim 8 wherein said disk is mounted on a hollow rotatable shaft, and said seat is mounted on a valve body having a passageway formed therein.

10. A valve position indicator as defined in claim 9 wherein said first coil leads pass through the hollow portion of said shaft for connection to an electrical cable and said second coil leads extend through the passageway of said valve body for connection to said electrical cable.

11. A valve position indicator as defined in claim 8 wherein said coils are electrically insulated from each other for operation as a transformer.

12. In a fire protection sprinkler system of the type including buried feed mains to supply Water to risers located in a plurality of buildings being protected, said feed mains having control valves adapted to open and shut the Water flow to each of said risers, the improvement wherein each of said control valves comprises a movable valve member, a first coil arranged on said valve member, a valve seat, a second coil arranged on said valve seat adjacent to said valve member, wherein said one coil induces a voltage in said other coil when energized by a voltage source, the magnitude of said induced voltage being dependent on the position of said valve member and said valve seat.

13. A system as defined in claim 12 wherein one of said coils is connectable to a soure of alternating voltage and the other of said coils is connectable to an indicator device.

14. A system as defined in claim 13 further comprising electrical cable means connected between each of said valves and a central station to provide an indication of the position of each of said valves at said central station.

15. A system as defined in claim 14 further comprising control means mounted in each of said valves to control the opening and closing thereof.

16. A system as defined in claim 15 further comprising second cable means connected between each of said valves and said central station to provide control for each of said valves from said central station.

1 1 1 2 17. A valve position indicator comprising a valve mema supervisory current therethrough at all times to indicate ber, a first coil arranged on said valve member, a valve that said valve position indicator is operative. seat, a second coil arranged on said valve seat adjacent a to said valve member, one of said coils being connectable v t s Cited to a source of alternating voltage and the other of said 5 UN STATES PATENTS coils being connectable to an indicator device, wherein 2,503,851 4/1950 Show "V M 340 196 said one coil induces a voltage in said other coil when energized by said voltage source, the magnitude of said NEILQ READ Primary Examiner induced voltage being dependent on the position of said valve member and said valve seat, said one coil having MYER Assistant Exammer' 

7. A VALVE STRUCTURE COMPRISING A VALVE MEMBER, A FIRST COIL ARRANGED ON SAID VALVE MEMBER, A VALVE SEAT, A SECOND COIL ARRANGED ON SAID VALVE SEAT ADJACENT TO SAID VALVE MEMBER, SAID VALVE MEMBER BEING MOVABLE WITH RESPECT TO SAID VALVE SEAT SO AS TO VARY THE EXTENT OF COUPLING THEREBETWEEN, AND MEANS TO VARY THE COUPLING BETWEEN SAID COILS BY MOVING SAID VALVE MEMBER IN RELATION TO SAID VAVLE SEAT. 